Digital Manufacturing of Makyoh-Magic-Mirror for Difficult-to-Machine Material to Process

The Makyoh, or “magic mirror,” is a bronze mirror originating from ancient Japan. The mirror reflects an image on a distant wall when parallel light such as sunlight shines on it. Craftsmen with a great amount of cumulative experience and intuition have produced the Makyoh, and the skill of these craftsmen has advanced continuously. However, there are very few craftsmen today who can make Makyoh mirrors. The problem of the diminishing number of craftsmen, which is not confined to creating the Makyoh, has drawn considerable attention. There have been attempts to digitize the skills (or inferred knowledge) of these craftsmen. To maintain traditions into the future, it is important to assist producers with traditional craftsmanship who have long supported Japanese industry. Therefore, the digital manufacturing of a Makyoh using numerically controlled machining and polishing was attempted. In our first report, a new method to make the Makyoh using a machining center was demonstrated [1]–[3]. In the present report, the influence of the topography of a Makyoh surface was examined, produced by the line machining method, on the projected image. As a result, (1) with our method it was possible to make the makyoh using all three materials. (2) The difference in contrast between cutting on the outer side and on the inner side was large with a decreasing radius of curvature R in circular cutting. (3) We succeeded in processing complicated shapes by using straight lines and curved lines.